Floating and Sinking

Broad Question

How does the size of an aluminum ball affect sinking?

Specific Question

Will a small, medium, or large sized aluminum ball sink more?

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Variables

Independent Variable:

Size of ball

Dependent Variable:

Depth (cm) of sinking

Variables That Need To Be Controlled:

1. Amount of water
2. Same amount of aluminum
3. Difference in size

Hypothesis:

I hypothesize that the small ball will sink most, then the medium, and last the large.

Graph of Hypothesis:

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Experimental Design

I will conduct my experiment in the science class room with a teacher. I will do this experiment 9 times, 3 for each size. I will be recording the data on a spread sheet in google. My teacher will be taking pictures of the experiment.

Materials List

1. Water
2. Ruler
3. Bowl
4. Pencil
5. Aluminum foil
6. Computer
7. Camera

Detailed Procedure

1. Gather all materials for experiment.
2. Set up materials for experiment.
3. Set up bowl by putting it on the table.
4. Put water in the bowl.
5. Crumple up a piece of aluminum into a ball.
6. Put the aluminum ball in the bowl of water.
7. Take a ruler and measure on how far it sinks.
8. Write down the distance and do this 2 more times making ball smaller each time (3 times for each size).


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Background Research

- the more tightly packed something is the more density it’ll have
- Density is measured in kilograms per cubic meter
- the more mass the more density
- the least amount of density the more it’ll float
- weight depends on gravity
- measured in newtons
-when something sinks it moves down with gravity.
-when something sinks it causes the water to rise.
-something will sink if it weighs more than the water.
-water displaced depends on the weight of the object.
-the shape of an object can help it float.
-the amount of air can also help the object float.
-hollow objects float better than solid objects.
-if something floats or sinks depends on mainly density and buoyancy.
-weight is not the only factor of sinking and floating.
-something will float because a force equal to the weight of the water.
-fluid pressure increases in depth
-increased pressure is exerted in all directions
-there is an unbalanced upward force on the bottom of a submerged object

References

• Green, Dan. Physics Why Matter Matters. 1st ed. New York, N.Y: Kingfisher, 2008. Print.
• ""Pressure"." HyperPhysics. AAPT, Aug. 2000. Web. 25 Jan. 2012. <http://hyperphysics.phy-astr.gsu.edu/hbase/pbuoy.html>.
• "Sink or Float." BrainPOP Jr.. FWD Media, Inc. , 2012. Web. 19 Jan. 2012. <http://www.brainpopjr.com/science/forces/sinkorfloat/grownups.weml>.
• "Sink or Float." Science NetLinks. Thinkfinity, 2012. Web. 20 Jan. 2012. <http://sciencenetlinks.com/lessons/sink-or-float/>.

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Data Table

Graph

Photos

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Data Analysis

Conclusion

The original purpose of this experiment was to figure out whether or not the size of an aluminum ball affects the depth it sinks. (Small, Medium, Large) The results of the experiment were that the size of the aluminum ball did affect the depth it sank. The greater the size of the ball the less it sank. For example the average depth of the large aluminum ball sank was 2.57 cm. The average depth the small one sank was 2.97 cm.

Discussion

My hypothesis was that the small ball would sink most, then the medium, and last the large. My results do support my hypothesis. There is a relationship between the independent and dependent variables. Some patterns and trends that my data show are that the smaller ball sank the most with an average of 2.97 cm, the medium sank the second most with an average of 3.17 cm, and lastly the larger ball sank the least with an average of 2.57 cm.
I think the tests I did went smoothly. Staff assisted me in my experiment. Without assistance I wouldn’t have known what to do. Looking at my detailed procedure or more background research may have made the test run smooth without assistance. If I could improve my experiment, I would measure the mass and volume of the balls so I could get the density. Doing this would also make an interesting future study. Also, I would ask more questions on why I was doing what I was doing.